Samsung and Pohang University of Science and Technology (POSTECH) researchers have achieved a breakthrough by developing a new type of ultra-thin, flat lens, an achromatic metalens, that dramatically reduces common image distortions. Unlike traditional curved lenses, metalenses are made of nanoscale structures arranged on a flat surface. This design not only slims down the lens significantly (often to less than 0.5 mm thick) but also minimizes the weight, making it highly attractive for applications in compact devices.
One major challenge with metalenses has been chromatic aberration, a common optical issue where colors are not focused at the same point, resulting in blurry or fringed images. In conventional lens design, each tiny part (or metastructure) is designed separately, often overlooking how they interact with each other. The research team addressed this by redesigning the process: they considered all the tiny structures together during the design phase, allowing them to effectively eliminate chromatic aberration after the lens is made.
In addition to fixing color distortions, this innovative lens design shortens the focal length which further contributes to reducing the lens’s overall size and weight. The team has even managed to produce metalenses that are 3–5 times larger in area without sacrificing their focusing ability.
Reference
Choi, M., Kim, J., Moon, S. et al. Roll-to-plate printable RGB achromatic metalens for wide-field-of-view holographic near-eye displays. Nat. Mater. (2025). https://doi.org/10.1038/s41563-025-02121-0
